Mempool API

Overview

Measurement Record

What actually happened when we called this API from our own infrastructure. Every value below was recorded by the request, not copied from the provider's documentation.

Request

GET https://mempool.space/api/v1/fees/recommended

Result

HTTP 200 · application/json · 74 bytes

Response time

46 ms (median of 3) · fastest 27 ms

Transport

TLSv1.3 · TLS_AES_256_GCM_SHA384 · certificate issued by Sectigo Limited

Browser CORS

Allowed — Access-Control-Allow-Origin: *

Served by

nginx

Recorded

2026-08-10

Fields Returned

Top-level fields present in the response we captured, with the type and value we actually received.

Captured Response

Captured from a real request to https://mempool.space/api/v1/fees/recommended on 2026-08-10. Long arrays and nested objects are truncated to keep the shape readable.

{
  "fastestFee": 4,
  "halfHourFee": 3,
  "hourFee": 1,
  "economyFee": 1,
  "minimumFee": 1
}

Implementation Example

Calls a real endpoint of this API. Replace any placeholder credentials with your own key.

const url = "https://mempool.space/api";
const response = await fetch(url);
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

import requests

url = "https://mempool.space/api"
headers = {}

response = requests.get(url, headers=headers, timeout=30)
response.raise_for_status()
data = response.json()
print(data)

curl "https://mempool.space/api/v1/fees/recommended"

What Can You Build?

// Fetch current cryptocurrency prices
const response = await fetch(`https://mempool.space/api`);
const data = await response.json();
const coins = data.data || data.coins || data;
const top5 = Array.isArray(coins) ? coins.slice(0, 5) : [coins];
top5.forEach(coin => {
  console.log(`${coin.name || coin.symbol}: $${coin.price || coin.current_price}`);
});

// Track portfolio value with current prices
const holdings = { BTC: 0.5, ETH: 2.0 };
const response = await fetch(`https://mempool.space/api`);
const data = await response.json();
let total = 0;
Object.entries(holdings).forEach(([symbol, amount]) => {
  const price = data[symbol]?.usd || 0;
  total += price * amount;
  console.log(`${symbol}: ${amount} x $${price} = $${(price * amount).toFixed(2)}`);
});
console.log(`Total portfolio value: $${total.toFixed(2)}`);

// Monitor price and trigger alerts
const ALERT_THRESHOLD = 50000;
const response = await fetch(`https://mempool.space/api`);
const data = await response.json();
const price = data.price || data.bitcoin?.usd || 0;
console.log(`Current BTC price: $${price}`);
if (price > ALERT_THRESHOLD) {
  console.log('🚀 Price alert: BTC is above $' + ALERT_THRESHOLD);
}

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

How This API Fails

We deliberately sent this API a broken request and recorded exactly what came back on 2026-08-10. Knowing the shape of an error before you hit it makes error handling much easier to write.

Common Errors & Troubleshooting

Generated guidance based on this API's documentation, not observed by us. Treat it as a starting point and check against the provider's own error reference.